Abstract
Purpose :
Previous studies that have reported an association between earlier age at menarche and increased risk of myopia typically involved older women, in whom the presence of cataracts may confound this relationship. Additionally, pregnancy is linked with short term changes to refractive error and its related phenotypes, though reports on long term changes have been limited. We conducted a cross-sectional exploration on associations of age at menarche with refractive error and ocular biometry in young adult women. We additionally compared longitudinal changes in refractive error and its related phenotypes in between parous and nulliparous women.
Methods :
Participants comprise the Raine Study’s Gen2 cohort, which is a birth cohort that have been followed since their prenatal periods. Information on age at menarche was collected prospectively via questionnaires when participants were 10, 14, and 17 years old. Participants underwent measurements of their spherical equivalent refraction (SER; cycloplegic autorefraction), keratometry (autokeratometry), axial length (IOLMaster), and crystalline lens thickness (Oculus Pentacam) when they were 20 years old. A subset of participants returned for a follow-up at 28 years old. Participants were excluded if they were currently pregnant or breastfeeding, had previous corneal surgery, or wore orthokeratology lenses.
Results :
A total of 429 were included in the cross-sectional analysis. After controlling for parental myopia and ocular sun exposure, there were no significant associations between age at menarche and presence of myopia, SER, or its related phenotypic measures. For the longitudinal analysis, 269 women were included in the analysis, including 35 (9.5%) parous women (at least one pregnancy to full term). Over the 8 years, there was a significant decrease in SER, and increases in axial length, corneal radius, and lens thickness. However, only the longitudinal change in lens thickness was significantly linked with parity. For each pregnancy carried to full term, rate of crystalline lens thickening increased by 0.004 mm/year (95%CI= 0.002 to 0.007), after controlling for parental myopia and ocular sun exposure.
Conclusions :
There is no association between age at menarche at myopia or its related measures. While pregnancy appears to result in thicker lens in the long term, there is no lasting effect on refractive error.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.